Will G.fast availability distance increase?

Hi

My cabinet is G.fast enabled, but my line length is too long for it to be available to me. My line is just over 400m from the cab, which was confirmed by a recent engineer visit. From researching availability on DSL checker and doing some rough measurements on Google Maps, G.fast seems to be currently available to line lengths up to approximately 250m.

I know that the G.fast speed decreases drastically as distance increases, but from looking at various articles online, it could reach up to around 100Mbps on a good quality line of my length.

Does anyone know if OR plan to increase the availability of G.fast to longer lengths at any point on the future?

Thanks in advance

Nope. The problem is that the G.fast omits the low frequencies used by ADSL and VDSL, to avoid interference. But the lower frequencies are the ones which propagate best over longer distances. So on longer lines (>300m), VDSL is faster than G.fast.

At the time G.fast was chosen, it was expected that Openreach/BT would have installed G.fast pods in DPs and on telegraph poles, so distance was not really an issue. That idea has been abandoned.

If they'd wanted long range *and* high speed, they would have chosen VDSL profile 35b. But that's a completely different technology, and they went with G.fast instead. They are highly unlikely to change technology at this stage.

Do you currently get a full 80Mbps download speed - if not you won't be getting G.fast as the higher frequency signals degrade too quickly. Personally I expect the distance to be reduced further as BT find premises on the current G.fast edge don't get a stable connection and have reduced upload speeds compared to VDSL.

In theory ~500m is possible but the speed drop is such that you'd be better with standard fttc (faster and more stable)

Now perhaps when adsl etc is switched off there may be some small gains for G.Fast but not much. Fttp is the future.

In reply to a post by brookheather:

Do you currently get a full 80Mbps download speed - if not you won't be getting G.fast as the higher frequency signals degrade too quickly

This is what I find hard to understand. I am at least 450m from the cabinet and I do get the full 80/20 but I am assuming that I won't be able to get G.fast because of the distance.

In reply to a post by derby13:

Hi

My cabinet is G.fast enabled, but my line length is too long for it to be available to me. My line is just over 400m from the cab, which was confirmed by a recent engineer visit. From researching availability on DSL checker and doing some rough measurements on Google Maps, G.fast seems to be currently available to line lengths up to approximately 250m.

I know that the G.fast speed decreases drastically as distance increases, but from looking at various articles online, it could reach up to around 100Mbps on a good quality line of my length.

Does anyone know if OR plan to increase the availability of G.fast to longer lengths at any point on the future?

Thanks in advance

My lines confirmed length of around 309 M which they said was borderline and i sync at:

196 / 37

Engineer seemed to think at around 350 M you would lose another 100 MB and then tails off massively.

In reply to a post by kasg:

This is what I find hard to understand. I am at least 450m from the cabinet and I do get the full 80/20 but I am assuming that I won't be able to get G.fast because of the distance.

Perhaps you live in an area with a small amount of subscribers on FTTC so there is less crosstalk enabling you to sync at max. rate? Maybe even vectored? Still out of range of G.fast with the current amendment, regardless. The general consensus is that you should be getting the full 80/20 to stand a chance of benefitting from G.fast, though still depends on length, gauge and crosstalk.

In reply to a post by J_Walsh:

My lines confirmed length of around 309 M which they said was borderline and i sync at:

196 / 37

Engineer seemed to think at around 350 M you would lose another 100 MB and then tails off massively.

That's pretty reasonable for ~300M. On the DSL checker, what sort of estimates did they/do they give you? Was it showing as Amber initially there? Do you know what gauge of wiring you have?

Wire gauge and material also affect line performance and the speed versus distance graphs usually only predict performance on the standard gauge copper wires. In rural areas on long lines the gauge can be thicker so line performs better at a given distance.

e.g. I have one line which Openreach advised was 350m and the max attainable sync reported by the modem is significantly more than the max FTTC of 80/20, last time I checked it was reporting 120/30 or thereby.

Edited by deleted (Tue 15-Jan-19 17:17:04)

In reply to a post by j0el:

In reply to a post by J_Walsh:

My lines confirmed length of around 309 M which they said was borderline and i sync at:

196 / 37

Engineer seemed to think at around 350 M you would lose another 100 MB and then tails off massively.

That's pretty reasonable for ~300M. On the DSL checker, what sort of estimates did they/do they give you? Was it showing as Amber initially there? Do you know what gauge of wiring you have?

DSL checker seemed to think i would get 260 MB Down and 40 UP but obviously with the confirmed line length that isn't going to happen. (Estimate has changed now too what i have).

Not too sure on the wire gauge